Objective: A tunable CMOS active inductor/resonator based Voltage Controlled
Oscillator (VCO) has been presented. In the design of LC-VCO, LC resonator (tank) circuit has been
substituted with gyrator based CMOS active inductor/resonator. The purity of VCO output signal is
defined by the phase noise parameter.
Methods: For good spectral purity of VCO output signal, the phase noise should be minimum.
Moreover, the quality factor of LC resonator is inversely proportional to the phase noise of VCO
output signal. In the presented work, a high-quality active inductor/resonator circuit has been used to
design VCO which minimizes the phase noise and chip area as well. Further, other VCO
characterization factors are measured.
Result: The designed circuit has been implemented in 0.18!! CMOS technology.
Conclusion: The design of the proposed AI based voltage controlled oscillator shows better phase
noise, less chip area and high output power. The high output power is achieved at the cost of limited
tuning range of 1.14 GHz ~ 2.1 GHz. The presented active inductor based voltage controlled oscillator
can be used for RF applications from 1.14GHz ~ 2.1GHz.